Being compared to Nadal is high praise because he's one of the greatest tennis players who ever lived. Sinner and Nadal don't play tennis similarly because the Italian plays more flatly than Nadal and is quite a bit more aggressive.
One thing they have in common is their mentality. Sinner has proven himself to be cold in high-pressure situations, which is something the Spaniard is known for. That's one thing both Nadal and Sinner have in common, but it's not the only thing.
They also turned around a 0-2 deficit against Daniil Medvedev in the Australian Open final. It was the crowning moment of his career, and talking about it to Corriere della Sera, Panatta praised his compatriot.
"He is a complete tennis player, with a mentality that allows him to no longer fear anyone. He is cold, he does not tremble at anything. The head: everything comes from the head..."
"From that point of view, Jannik reminds me of Nadal, someone who doesn't give up a 15, who fights on the first ball of the match as if it were the last. And the nice thing is that, at 22 years old, he still has a lot of room for improvement."
Sinner is certainly in a really great sport right now. He's been one of the best players in the world for a while and is set to become only better in the future. Panatta is delighted about it because he sees Sinner as the perfect product of his country.
"Jannik is an excellent export product of our country, he only transmits values: he is polite, intelligent, respectful of everyone, with a sense of humor, which doesn't hurt. He is a decent person, never over the top."